Re: only a single core (out of 8) initialized

From: david
Date: Fri Jun 05 2009 - 12:48:21 EST


On Thu, 4 Jun 2009, Andrew Morton wrote:

On Thu, 4 Jun 2009 19:52:36 -0700 (PDT) david@xxxxxxx wrote:

this is 2.6.30-rc7

Were any earlier kernels OK?

sorry, I missed this question.

I was running 2.6.29.1 when I noticed this problem. I haven't tried older kernels yet.

David Lang

with a patch added to debug a nv sata driver
incompatibility with the Intel SSDs on a tyan motherboard

on one system it sees all 8 cores, on the other system it only initializes
one core.

can anyone help me spot what's going wrong in the one that's only seeing a
single core? If I'm reading things correctly it's seeing both sockets for
the NUMA setup, but then only initializing one core on the first socket.

good:
SMP: Allowing 8 CPUs, 4 hotplug CPUs

bad:
SMP: Allowing 1 CPUs, 0 hotplug CPUs

perhaps due to
ACPI: No APIC-table, disabling MPS

You could have a poke around in arch/x86/kernel/smpboot.c() and find
out what happened here. I'd be suspecting this code triggered:

/* no processor from mptable or madt */
if (!num_processors)
num_processors = 1;

because ACPI doesn't like that board.

Did you look into updating the BIOS?


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